Pump and method of regulating the same



July 3, 1923.

PUMP AND METHOD OF REGULATING THE SAME L. F. MOODY Filed July 5, 1919 2 Sheets-Sheet 1 18 M 30 21 7 29 19 2 Z 23 12 S z 27 15 u 26 8 21/ j// /7 V g I 4 E L l/ July 3, 1923. 1,460,428

L. F, MOODY PUMP AND METHOD OF REGULATING THE SAME Fil ed July 5, 1919' 2 Sheets-Sheet 2 INVENTOR Patented July 3, 19 23.

' UNITED- STATES LEWIS rnaza v iuoonY, or PHILADELPHIA," rmmsvnvmm.

PUMP AND METHOD OF BEGULATING TEE SAME.

Application filed July 8,

[a all whomit may concern:

Be it lmown that I, LEWIS F. MOODY, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Pumps and Methods of .Regulating the Same, of which the following is a specification.

This invention relates to and methodsfor regulating the same an particularly to such pumps having a rotary impeller. The object of the invention is to provide a pump and method of control therefor whereby the amount of water pumped may be regulated within wide limits while maintainin highly efficient flow conditions at all ad ustments.

A common methodof regulating pumps is by means of a gate valve or some similar 7 valve in the discharge pipe for throttling the flow after the water has left the pump. 'Such a valve usually reduces the flow by interposing a loss of head and thus controls the pump mainly by reducing its efliciency.

In the pump of this invention regulating means is provided in'the pump inlet leaving the outlet free from obstruction and supplying the impeller with a widely variable hydraulic pumps quantity of water in such manner that efficient conditions of flow at both the inlet and outlet are maintained at all dgrees of opemng. Y

Other objects and advantages of the invention will appear in the following description. taken in connection with .the accompanying drawings in which:

Fig. 1 is avertical section of a pump illustrating one embodiment, and

Fig. 2 is a vertical section of a modified form of pump.

In. the pump shown in Fig. 1 power is supplied from couplin 5 and shaft 6 to rotate impeller blades which are of the 46 axialscrew type and draw water from the inlet casing 8 and drive it through outlet casing 9. The inlet casing 8 is spiral or volute in form narrowing the flow and directing it radially inward through the gate 59 space 11 to the transition space 12 where it is turned into the axial direction to pass to the impeller blades 7. In the outlet casing 9 the flow from the impeller is turned into radial planes and gradually broadened .1919. Serial 110. 808,807.

. in section. In passing through the pump the flow in the inlet isincreased in velocity so that it hasits pressure head transformed largely 1nto velocity head at the impeller blades 7 while in the outlet thevelocity of flow is gradually reduced retransforming' the velocity head into pressure head muc higher in degree, of course, than that at the inlet. The inlet casing 8 is bolted to the outlet casing as at 15 and has a detachable d head 16 with its inner end 17 conical and curved to form the central guiding sure faces of the transition space 12. The

hub 18 of the. impeller has its surfaces curved to merge smoothly with these transition surfaces and outlet passage as shown and the impeller shaft 6 runs in bearings 19, 20 and, 21 in tubular housing 22 integral with the outlet casing 9. Stationary vanes 23 and 24, shaped to conform to the paths of flow, reinforce the outlet casing walls.

In order to regulate the output of the I pump, movable guide vanes "01-; wicket gates 25 are interposed in the inletf to vary the amount of water suppliedto the impeller. These vanes are pivotally mounted .in bearings in the casing 8 and head 16 and their sp1ndles-26 pass through head 16 and are keyed to cranks 27 for adjustment, the Y cranks in turn, being linked at 28 to the rotatable adjusting ring 29 .fitt'ed to the-cylindrical bearing 30 of the-head 16. The adjusting ring would be moved by an extension arm and a draw rod connected to a piston or hand wheel as desired and all of the vanes are moved in exactly similar mannor and are therefore given equal'relative angular positions at all openings. The

guide vanes 25 may be arranged both to ,close to smaller amounts of opening than their normal position and to open to positions for greater discharge than normal and their number and length are preferably such that they may be closed to shut ofifthe'sup ply to the pump altogether. The water is brought to in the spiral passage of the inlet casing and after passing through the wicket gates 25 in a radial inward flow direction and being given an additional whirling motion by the gates, the water is guidedeinto a' substantially axial flow direction where it enters the impeller in a continuous revolv 1 the wicket gates ing stream of substantially uniform velocity around the circumference. By this means the flow through the pump is regulated let is that it leaves the outlet clear of obstruction and free to be designed to secure the most etficient transformation of the velocity head at the impeller into pressure head at the outlet. Adjustable guide vanes in this outlet passage would break up the continuity of the diifusion and introduce wasteful disturbances; for the passa es through the Hide vanes are too short in comparison with their width to be effective as difi'users and, if very long vanes are used, the heavy mechanical load required to adjust them makes them. impractical and the additional friction due to the large aggregate amount of surface on the vanes would introduce serious hydraulic losses. These objections are not involved when the vanes are placed on the entrance s1de of the impeller since at this point in a pump the water is being accelerated and the passages between the vanes contract in area instead of expanding; The vanes may be formed to give highly efiicient flow conditions at all angles of opening, acting simply to. vary the amount of the flow and imparting a slightly variant angle of impact at the impeller blades.

In the structure illustrated in Fig. 1 the radial flow inlet passage permits the gate vanes to he set on parallel axes and controlled by the simple adjusting mechanism shown. Where it is desirable to use an axial flowv inlet passage the gate vanes may v ther continue the whirl in the space and the impeller 3 It is essential that a be of the axial flow type with axes radiating from the am's of the pump as shown in Fig. 2. The water enters this pump in an axial direction at the inlet 30, is given an initial whirling motion by a series of fixed vanes 31, and is discharged from these vanes into the .wicket gates 32 which furidance and discharge the water with a; increased amount of ihetween the wicket gates sufiicient space beprovided between the entrance vanes and impeller. to allow the water" to come together in a continuous revolving mass. of substantially uniform velocity around the. circumference before it enters the impeller. The guide vane axes in Fig. 2 am in the same plane although they might equally wellcontained in a nee les mediate links 41, the 'end pins of which are inclined so that all their axes intersect the pump axis at the same point as the intersection of the spindle axes. in all positions of the wicket gates the pins mounted on the levers will continue to in- Therefore,

tersect the same fixed point and a correct s fit at all the pivots may be maintained.

The cone 37, ring 36 and the hub 43 of the impeller merge smoothly in contour with each other and with the central walls.

of the outlet casing 39. The outer walls of the inlet and outlet casings are also formed to merge with each other and gradually decrease the section and increase the velocity of the inflow to the impeller and then conversely increase the section and decrease the'velocity of the outflow therefrom to retransform the velocity head into pressure head at the outlet. The guide vanes 32 are formed with their outer edges shaped to fit the inlet casing walls 30 when they are closed; and with their inner edges shaped to fit the ring 36 which is made spherical in the portion coming in contact with the vanes.

It will be understood that the invention 1. The method of regulating the flow.

through a rotary pump comprising increasing the velocity of the inflow in the direction of flow and simultaneously varying the angle of whirl thereof.

2. The method of regulating the flow through a rotary pump comprising imparting an initial whirl to the inflow and subsequently increasing this whirl in variable manner. g

3. The method of regulating the flow through a rotary pump comprising directing the inflow on whirling lines around the impeller axis as a center, and increasing the velocity of the inflow and variably changing the angle of whirl in advance of the impeller to regulate the flow through the pump.

4. The method of pumping a fluid comprising directing said fluid on initially whirling lines around an impeller axis, varying the angle of whirl to regulate the flow through the pump, and applying an impeller to increase the'whirl, andguiding the Whirling flow away from the impeller in an axially progressing spiral course of expanding cross section.

5. The methodof pumgin a fluid'comprising directing said uirI on initially whirling lines around an impeller axis, increasing thev whirl oin variable manner, and applying an impeller to-increase the whirl, and guiding the whirling flow away from the impeller in an axially progressing spiral course of expanding cross section. 1

6. Ina rotary h draulic pump the combination with an impeller, of inlet means adapted to form the inflow into an axially progressingstream whirling around the impeller axis, and means for varying the angle of whirl of said stream to regulate the flow through the pump.

7. In a pump the combination with an impeller, of an inlet casing imparting a whirl to the inflow and directing it axially with increasing velocity as it approaches said impeller, and means for varying the angle of-whirl of the inflow to regulate the pump.

.8. A rotary hydraulic. pump having. in combination an impeller, an inflow conduit,

and an outflow conduit, said conduits and the impeller being disposed so that, the course of the water flow through the pump shall be in a continuously advancing helical path first converging to its smallest cross section at or near the impeller and then diverging therefrom, the inflow conduit having means to impart a variable angle of whirl to the flow so as to regulate the flow through the pump. A

9. In a rotary hydraulic pumpthe combination with a radially directed inflow .conduit having means to impart a variable whirl to the inflow, of guiding means forming a transition space turning the flow from, radial to axial and axially advancing the flow and delivering it to an impeller of the axial flow type. v

10. In a rotary hydraulic pump the combination with a radially directed inflow conduit having means to impart a variable whirl to the inflow, of guidlng means form'- ing a transition space turning the flow from radial to axial and axially-advancing the flow'and delivering it to an impeller, and an outfiow conduit adapted'to discharge the flow along divergent helical paths with decreasing velocity.

11. In a ump the combination with a rotary impe er, of an inlet directing the inflow axially to said-impeller, and movable uide vanes regulating the flow through said inlet, all of said guide vanes being linked to a single operating ring to be similarly adjusted thereby, said movable guide, vanes turning on axes parallel to the axis of said operating ring.

12. In a pump he combination with inlet and outlet casings bolted together, of central guiding means carried by said in-' let casing, a rotary impeller also having central guiding surfaces mergin with the central guiding surfaces of sai inlet casing, central guiding surfaces in said outlet oasing merging with the contour of said impeller so that the flow is first narrowed and thenexpanded in section, and means in said inlet for varying the direction of the flow therethrough. r

13. In a ump the combination with an impeller, 0 an inflow passage graduallv narrowing in section to increase the "elocityof flow, and an outlet passage pro- -vided by a volute casing of increasing cross section, and means in said inflow passage for controlling the flow through said pump comprising a series of adjustable gate vanes adapted to impart a whirl to the inflow.

14. In a pump the combination with an" impeller of the axial flow type, of an inflow passage narrowing in section to increase the velocity of flow, an outlet passage provided by a volute casing of increasing cross section, and means in said inflow passage for controlling the flow throu h said pump comprising a series of adjusta le gate Eanes adapted to impart a whirl to the in- 15. In a hydraulic pump the combination. with an axial flow impeller, of guiding means forming a converging transition space in advance thereof, adapted to guide the flow in an axial direction and inwardly directed guiding means in advance of said transition space adapted to impart a whirl to the flow so that the inflow is in the form of a continuous whirlingstream of decreasing cross-sectional area turning into the direction at the entrance to the impeller.

.directionat the entrance into the impeller.

18. In a pump the combination with an impeller of an inlet conduit adapted to impart a whirl. to the inflow and a. series of guide vanes arranged in the path of said inflow and adapted to increase the whirl.

19. In a pump the combination with an impeller of an inlet conduit, adapted to impart a whirl to the inflow anda series of inwardly directed guide vanes arranged in the path with said inflow and adapted to increase the velocity and whirl thereof. I

20. In a pump the combination with an impeller of an inlet conduit adapted to impart a whirl to the inflow, a series of inwardly directed guide vanes arranged in. the path with said inflow and adapted to increase the velocity and whirl thereof, means for adjusting the position of said vanes to regulate the flow.

21; In a pump the combination with an impeller of an inlet conduit adapted to impart a Whirl to the inflow and a series of inwardly directed guide vanes arranged in the path of said flow and adapted to inwherein the flow may merge into a solid stream. i

22. In a hydraulic pump the combination with an impeller, of means for guiding the flow thereto comprising a radial intake passage adapted to impart a whirl to the flow, and a transition space between said passage and said impeller adapted to turn the flow toward the axial direction.

LE IS FERRY MOODY. 

